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From 0ef054c3e7d7423d0f18edd7a29f62a9c6a811b4 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 27 Sep 2022 16:21:26 +0200
Subject: [PATCH 36/96] kernel: add a config option for keeping the kallsyms
table uncompressed, saving ~9kb kernel size after lzma on ar71xx
[john@phrozen.org: added to my upstream queue 30.12.2016]
lede-commit: e0e3509b5ce2ccf93d4d67ea907613f5f7ec2eed
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
init/Kconfig | 11 +++++++++++
kernel/kallsyms.c | 8 ++++++++
scripts/kallsyms.c | 12 ++++++++++++
scripts/link-vmlinux.sh | 4 ++++
4 files changed, 35 insertions(+)
diff --git a/init/Kconfig b/init/Kconfig
index c7900e8975f1..4d5f1ee66139 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1475,6 +1475,17 @@ config SYSCTL_ARCH_UNALIGN_ALLOW
the unaligned access emulation.
see arch/parisc/kernel/unaligned.c for reference
+config KALLSYMS_UNCOMPRESSED
+ bool "Keep kallsyms uncompressed"
+ depends on KALLSYMS
+ help
+ Normally kallsyms contains compressed symbols (using a token table),
+ reducing the uncompressed kernel image size. Keeping the symbol table
+ uncompressed significantly improves the size of this part in compressed
+ kernel images.
+
+ Say N unless you need compressed kernel images to be small.
+
config HAVE_PCSPKR_PLATFORM
bool
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index fbdf8d3279ac..f30ecfedd293 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -81,6 +81,11 @@ static unsigned int kallsyms_expand_symbol(unsigned int off,
* For every byte on the compressed symbol data, copy the table
* entry for that byte.
*/
+#ifdef CONFIG_KALLSYMS_UNCOMPRESSED
+ memcpy(result, data + 1, len - 1);
+ result += len - 1;
+ len = 0;
+#endif
while (len) {
tptr = &kallsyms_token_table[kallsyms_token_index[*data]];
data++;
@@ -113,6 +118,9 @@ static unsigned int kallsyms_expand_symbol(unsigned int off,
*/
static char kallsyms_get_symbol_type(unsigned int off)
{
+#ifdef CONFIG_KALLSYMS_UNCOMPRESSED
+ return kallsyms_names[off + 1];
+#endif
/*
* Get just the first code, look it up in the token table,
* and return the first char from this token.
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index f18e6dfc68c5..262a3799bae1 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -58,6 +58,7 @@ static struct addr_range percpu_range = {
static struct sym_entry **table;
static unsigned int table_size, table_cnt;
static int all_symbols;
+static int uncompressed;
static int absolute_percpu;
static int base_relative;
@@ -487,6 +488,9 @@ static void write_src(void)
free(markers);
+ if (uncompressed)
+ return;
+
output_label("kallsyms_token_table");
off = 0;
for (i = 0; i < 256; i++) {
@@ -538,6 +542,9 @@ static unsigned char *find_token(unsigned char *str, int len,
{
int i;
+ if (uncompressed)
+ return NULL;
+
for (i = 0; i < len - 1; i++) {
if (str[i] == token[0] && str[i+1] == token[1])
return &str[i];
@@ -610,6 +617,9 @@ static void optimize_result(void)
{
int i, best;
+ if (uncompressed)
+ return;
+
/* using the '\0' symbol last allows compress_symbols to use standard
* fast string functions */
for (i = 255; i >= 0; i--) {
@@ -774,6 +784,8 @@ int main(int argc, char **argv)
absolute_percpu = 1;
else if (strcmp(argv[i], "--base-relative") == 0)
base_relative = 1;
+ else if (strcmp(argv[i], "--uncompressed") == 0)
+ uncompressed = 1;
else
usage();
}
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index eecc1863e556..8b8c9000892a 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -156,6 +156,10 @@ kallsyms()
kallsymopt="${kallsymopt} --base-relative"
fi
+ if [ -n "${CONFIG_KALLSYMS_UNCOMPRESSED}" ]; then
+ kallsymopt="${kallsymopt} --uncompressed"
+ fi
+
info KSYMS ${2}
${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${2}
}
--
2.37.2
|
